Automatic fire-alarm system



Sept. 2, 1930. w. s. PIPER AUTOMATIC FIRE ALARM SYSTEM Filed April 29, 1926 2 Sheets-Sheet 1 Sept. 2, 1930. w. s. PIPER 1,774,995

AUTOMATIC FIRE ALARM SYSTEM Filed April 29. 1926 2 Sheets-Shoot 2 WITNESS! A2 2 E; fW

a A 21W ATT RNEY Patented Sept. 2, 1930 UNITED STATES WILLIAM S. PIPER, OF LIBERTY, MISSOURI AUTOMATIC FIRE-ALARM SYSTEM Application filed April 29,

This invention relates to improvements in automatic fire alarm systems, and refers more particularly to an automatic fire alarm device which may be located at any desired point in a structure or building,including dwellings, industrial structures, manufacturing buildings or storage warehouses, and may be used in apartment buildings when attached to electric annunciators.

The novelty in the invention lies primarily in the utilizing of a fusible link in connection with a gravity switch which, when closed, completes an electric circuit and rings an automatic alarm.

Fig. 1 is a view of a small dwelling or gambrel roof with the device in place.

Fig. 2 is a plan view of the construction shown in Fig. 1 with part of the roof broken away to show the positioning of the device.

F 3 shows an electric circuit and the fire Fig. 4 is an enlarged detail of the device as installed.

F f. 5 is a view taken along the line 5-5 in I, 4, looking in the direction of the arrows.

Fig. 6 is an edge view of the device shown in Fi l.

F. 7 is a modified type of construction in whici the fusible link is mounted upon the exterior of the box containing the switch,- that is, the box is placed inside of a wall and only the link being outside of the box.

Fig. 8 is a view showing the construction of Fig. 7 and taken from the opposite side of the switch box.

Fig. 9 is a view taken along the line 9-9 in Fig. 7.

Referring to the drawings, at 1 in Fig. 1 are shown rafters supported by perpendicular lateral joists 2 and a ridge pole 3. The simplest type of building construction is shown, as the building in which the device is used forms no partof the present invention. In Fig. 1 the circuit closers are positioned at any predetermined point such as at 4 along the rafters and also at 4 on the perpendicular joists. The circuit closer is shown in detail in. Fig. 4c and consists of a switch box 5 in which is mounted a gravity switch '6 having a support member 7 to which is pivoted at 8 a 1926. Serial No. 105,476.

bell crank 9 at the outer extremity of which is mounted a weight 10. At the opposite eX- tremity of the bell crank designated as 9 is attached a secondary connection 11 which, in turn, is connected to a fusible link 12. This latter link 12 consists of two pieces of metal soldered together by means of a metallic sollering material of a predetermined melting point. This solder is adapted to melt at a temperature which is recognized as a proper temperature by the Fire Underwriters Laboratories. This link has eyes at both ends, designated as 12 and 12 one eye member attached to a stationary hook member 13 and the opposite eye designated as 12 attached to 1e secondary connection 11. The stem 9 of the bell crank nas the form of a knife-edge sw tch which is adapted to fall between the biQUYCfll'GCl portions of the contacting mem bers of the switch 6 designated as 13 in the drawings. The switch has electric connection 14 and 15 with the circuit wires 16 and 17, respectively, in which circuit are interposed the alarm bell 18 and-the battery 19. The principle of the device, which is very simple in operation relying wholly upon gravitational forces, consists of the closing of the circuit due to the falling of the weighted switch with the fusing of the link 12.

The modified form of construct-ion is shown in Figs. 7 and 8 and 9 and differs in this con struction relative the one described consisting in mounting the link 12 upon the switch box instead of arranging it as shown in Fig. 4. The modified type of switch would be more adaptable to a location where the room for the device was limited.

In the drawings the device is shown mounted within a switch box. It is understood that while this construction would probably be less affected by deteriorating forces such as dampness and the collection of dust and dirt, the invention. is not restricted to the use of a device which is wholly enclosed or pan tially so. Furthermore, in place of having a special alarm circuit with a battery such as that shown in Fig. 3, the device may as well be connected in the light circuit by the use of a transformer and the alarm bell func- 

